Today, the trends of paper product development are to a growing extent decided by the buyers and by legislative measures. The buyers of printing papers want to save mailing costs and to cut the amount of waste generated. Waste management fees have also been imposed on packages, the amounts of which depend on the weight of the product. Generally, it appears that various energy and emissions taxes will have to be incorporated into the price of paper products, forming an extra cost load. For these reasons the paper buyers would like to have paper products of low grammage which, nevertheless, fill high quality standards. On the other, for the paper-based information distribution to be able to compete successfully with electronic media, it is required that the printing result of the paper products be further improved.
The above mentioned general trends put rather high requirements on the raw materials of the paper and on the manufacturing processes. Recently, in order to fulfil the requirements, extensive efforts have been made in order to improve the paper raw materials and the manufacturing processes thereof. It is an aim to manufacture high-quality papers by using smaller amounts of raw materials than before. When the grammage of the paper is reduced, the opacity of the paper become a critical feature. Opacity can be enhanced by increasing the filler content of the paper. This, however, reduces the strength of the paper and therefore efforts are being made to change the structure of the paper while still maintaining the important product properties. One additional property which is related to an increase of the filler and pigment amounts of paper and cardboard products is the increase of the residual ash, which makes it more difficult to utilize recirculation fibers e.g. in energy production and to destroy them by burning, respectively. Furthermore the present mineral based fillers and pigments cause great wear on the wire. This shortens the operational time of the wires.